Refrigerating apparatus



Nov. 3,1942. G. c. PEARCE REFRIGERATN- APPARATUS Filed Aug. 25, 1940 @www VENTOR. Y f

ATTORNEYS Patented Nov. 3, 1942 mIGlB-AHNG APPARATUS George C. Pearce, Dayton, Ohio, asignar to General Motors (lorporation,l

porationofDeiaware Dayton, Ohio, a eorappuuoa Amst zr, mo, serial Ns. stam s cum (01. zoo-ss) This invention relates to reirigerating apparatus and more particularly to controls.

The accuracy oi' control devices depends upon the accuracy of tn of movement between the operating means and the control device to be operated, such as a valve or switch. One of the important factors is the pivotal connectionof the levers .used in transmitting the movement. The usual types of pivotal connections involve friction and have a certain amount l of looseness or play which affect the accuracy of y the control. These inaccuracies are multiplied when compound leverage devices are used to amplify the movement provided by the operating means. l

It is an objectv of my invention to provide a control having an accurate compoimd multiplying arrangement.

It is another-object oi-my invention to provide a multiplying arrangement for controls in lwhich no pivot pins are required.

It is a further object of my invention to provide a multiplying arrangement for controls in which the pivotal connections are made subnantially frlctionless.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawingfwherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. l is a vertical sectional view disclosing one embodiment of my invention; and v Fig. 2 is a plan view oi the control shown in Fig. 1 with the cover removed. f Brieny, I have shown a diaphragm operating a compound multiplying arrangement in which flexible metal connecting members and a rounded adjusting screw are used instead of the usual pivot pins in order to provide a more accurate. '40

more compact and more durable multiplying arrangement for operating the switch mechanism.

Referring now to the drawing, there is shown a frame member 20, formed of heavy sheet'metal,

andi l di rti 22 d d 45 ne u ngabasepo on an folded upm e pivotal support forthe secondary member I8. In-

portions 24 and 28. Fastened to the base portion 22 is a pancake-shaped diaphragm 2l which has a threaded nipple `extending through an aperture in the base receiving a clamping nut for fastening theA diaphragm 2l to the base@ The 50 nipple connects to the capillary tubing 30 which connects the interior of the diaphragm with some suitable source of control pressure, such as the high or low pressure sides oi' the refrigerating system.

The oppositenor -upper face of the diaphragm 2l is provided with a rounded button bearing against a diaphragm follower 32 which is the primary member of the multiplying arrangement used and is analogousto the primary lever of ordinary. 'multiplying arrangements. However,

this primary member 82 is made of comparatively.;`

heavy metal and at one end is flrmlyriveted by means of the post 8l tothe base 22. l

v This primary member I2 is held in ,eontact with the button upon the upper face ofthe by a heavy compression type coil spring Il supported at itsmupperv-end by a spring follower {I} which irrturn is located by a set screw Il. This setscrewltisthreadedthroughasprlngsupport member 42 which is generally Z-shaped and has proiections u on opposite sides which are received in notches Il vprovided in the upper edges of the side vwall portions 2l and 2L". The upper portions of the edges of these notches are struck inwardly so as toiirmlyhold the' projectionsuinthebottomofthenotchesandto oppose any upward movement of the upper portion of the Z-shaped member 42. The lower portion of the Z-shaped portion 42 is supported by apairotposts I! whicharerivetedtothebase portion 22.

The primary member 32 is `provided with an odset end portion Il. Riveted by the rivets l2 to the ofiset projecting portions Il at the end of the primary member 32 is a thin leaf .spring member 'M .which` at its other end is riveted by a pair of rivets Il to the .secondary member Il. The secondary member Il is provided with shoulders Il which bear upon the mid-portion of the leaf spring member Il so that the pivot between the primary member l2 and the secondary member Il is `about the lower edges of these shoulders il which are in contact with the leaf spring member Il.

A set screw l2 is threadedthrough the center of the lower portion of the Z-shaped spring support member I2 and is provided with a rounded lower end which serves as the normally iixed asmuch as the primary and secondarymembers are substantially straight at all times; that is, they are substantially perpendicular to the'movement of the diaphragm 28 and the secondary member il at all times. There is substantially no friction between the secondary member il and the bottom of the set screw 62, since under such -circumstances there will be practically no lateral' movementof the secondary member Il rle'ld member Il which at its other end is riveted contact member 1l to a ilexible strip of which extends the same direction 'il and is the base by screws, One oi the electrical conductors Il various pieces of insulation from the metal portions oi the switch mechanism'to prevent arcing.

when the diaphragm Il expands, it will bend upwardlytbsireeendoftheprimarymember 82. The movement provided by the diaphragm Il is comparatively small so that this movement is always well within the elastic limit of the primary member t! and entails no great amount of force. This primary member by its bending movemsnttendstocurlslightlyandthisprovides an increase amplifying movement with respecttoaprimarylevefofeoualdimensions. The lower end of the set screw t! holds the adiecmt end of the secondary member Il from movement. This causes the offset end UI of the primarymemberlltobearthroughtheleaf springupontheadiscentedgesoftheshorul-` der Il of the secondary member Il to pivot the secondary member Il in a counter-clockwise direotion about the lower end ofthe set screw l2.

Thus the movement of the diaphragm Il, which has been amplined in the primary member n, is further ampliiied in the secondary member Il in proportion to the relative distance between the spring anchoring apertures in the member te and the lower end of the pivot pin l! on the one hand and the distance between the shoulders Il and the lower end of the-pivot pin It on the other hand. The-tension toggle springs 'le always innn'eatensionupontheleafspxingltandthe `oileet proiecting end Il oi the primary member ileupporbtheleaisprings llinbothdirections fromtheshmlldersllsothatnoshearstressis emertedupontheleaispringsll. Binceallof the members ane riveted together none are likely to become loose and the riveted connections between the primary member and the post 34 and the leaf spring connection between the primary member l! and the secondary member Il are substantially frictionless.

2l in order to coordinate the operation of the switch mechanism and the movement of the diaphragm 2l so that' the movement of the diaphragm 2l will take place only within certain limits. This adjustment may also be so set that the primary member moves equally in opposite directions from its natural position. The set screw Il may be used to control the tension oi' the compression spring It in order to determine the pressures at which the switch mechanism will be operated. Obviously the toggle mechanism could be used to operate a valve or some other control device instead of the contact 1l. While it has been mentioned that this switch mechanism may be used on a refrigerating sys tem it is obvious that it is also applicable to other apparatus.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it ls to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

l. A control including a compound multiplying device comprising a bendable primary member rigidly anchored at one point, a secondary multiplying member bodily carried by and rockably connected directly to the primary member to form a direct pivotal connection between the two members, a pivot for the secondary member, a control device operably connected to one of said members. an operating means operably connected to the other of said members for operating said members and said control device, and means for adjusting said pivot to adjust the relationship between said operating means and the operation of said members.

2. A control including a compound multiplying device comprising a bendable primary multiplying member rigidly anchored at one point. a rigid secondary multiplying member secured by and rockably connected directly to the primary member at another point to form a direct pivotal connection between the two members, a pivot for said secondary member, a control device operably connected to one oi" said members. -an operating means connected to the other of the members to operate the control dqice.

3. A control including a compound multiplying device comprising a bendable primary multiplying member rigidly anchored at one point, a rigid msecondary multiplying member, a lea! spring The set screw es may bsemploy'ed to' adjust the location of the primary and secondary members with respect to tbs buttonon' the diaphragm rockable connection directly connecting the secondary member with another point upon the primary member to form a direct pivotal connection between the two members, a pivot for said secondary member, an operating means connected to the'primary member to 'operate the control device.

4. A control including a compound multiplying device comprising a bendable primary multiplying member rigidly anchored at one point, a rigid seco ary multiplying member, a leaf spring roch le connection directly connecting the secondary member with another point upon the primary member to form a direct pivotal connection ,between the two members, a pivot for said secondary member, an operating means connected to the primary member to operate the control device, and means for adjusting said pivot to vary the relationship between said operating means and the operation of said members.

5. A control including a compound multiplying device comprising a bendable primary multiplying member rigidly anchored at one point. a rigid secondary multiplying member, a. leaf spring rockable connection directly connecting the secondary member with another point upon the primary member to form a. direct pivotal connection between the two members, a. movable means in operative relationship with the primary member,

a movable means in operative relationship with the secondary member, one of said movable means constituting an operating means for operating the control device, the other of said means constituting an adjusting device for adjusting the 5 operation of the control device.

GEORGE C. PEARCE.

CERTIFICATE OF CORREOTION. Patent No. 2,500,697. November, 19h2.

GEORGE C. PEARCE. A It `ishereby Aoertified that error appears in the printed specification of the above numbered'pstent requiring correction as follows: Page 2, second column, line lil, claim 2, for "secured" read supported-m; ncithat': the said Letters .Patent shquld be read with this Acorrection therein vthat the same may conform to the record of Ehe-'casein the Patent: Office.

signed and sealed this 12th day of Jamary, A. D. 1915.

Henry Ven Arsda le (Seal) Acting Commissiorier of Patents.

CERTIFICATE oF coRREoTIoN. Patent No. 2,500,697. November-'5, 19h2.

GEORGE C. PEARCE.' It .ishereby certified that error appears in the printed Specification of the above numbered'petent requiring correction as follows: Page 2, second column, line )41, claim 2, for "eecured" read supported-1' and'that che said Letters .Patent should be read with this Acorrection thereinthat the same may conform to the record of the -'casein the atent- Office.

signed and sealed this 12th day of- Jamary, A. D. 19M.Y

. Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

